Seeking advice, should I switch to a different weight Mobil 1?

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Jan 19, 2003
This is my first post here, so please forgive me for being a newb and for being long winded. I own 1 car, and 2 trucks. I live in central North Carolina. I change the oil and filters every 3000 miles or 6 months in the following applications.

1. 2001 Mustang GT, 15,000 miles, driven daily, Mobil 1 5W-30, Mobil 1 filter.

2. 2000 SVT F-150 Lightning, 7500 miles, not driven daily, Mobil 1 5W-30, Mobil 1 filter.

3. 1992 4.3L S-10, 125,000 miles, driven daily, Mobil 1 10W-30, Bosch premium filter.

I am not experiencing oil consumption in any of these vehicles. What I am concerned about is the utmost in protection from wear and high heat, especially in the supercharged Lightning. Would it be wise to switch the Mustang to Mobil 1 0W-30 or 0-40 and the Lightning to Mobil 1 15W-50?
i too am kinda new to these things as well! i have learned a great deal on this site i beleive. you will get as many different opinions here as colors of the rainbow but thats one of the things that makes it great! in my opinion, i would stick with the mobil 1, or another quality syn, such as the amsoil, in the viscosity that the owners manual states, and maybe go to oil analysis. i think that you might be changing the mobil syn way to early. you should be able to go at the least twice the 3 thou miles. i myself got trapped in the 3month, 3 thou routine. looking at the synthetics now with renewed intrest.
Personally I think you would be better off with the 10W-30 Mobil 1. Your manuals probably will allow it. Unfortunately manuals don't really differentiate between Syn and Non-Syn and no allowances are made for lower pouring points of the syn. I use 10W-30 here in Pa. My daughter in NC (Oxford) has the 10W also.

Unless you drive your Mustang extra hard 10W-30 would be OK. A better option for very hard driving would be 0W-40 or Delvac 5W-40. I would not go with the 15W. Another option would be to have perhaps a 25% solution of 15W-50 with 10W-30. I know most on here will not suscribe to this though. I do it in my truck because it decreases oil usage. Probably the Redline could give you a little more protection than the Mobil 1 on your Stang. As you spend time here you can check ut the Shaeffer oils. You would be safe at 6K miles. But for your pride and joy you might want to pull an analysis.

The GT could use 0W-30 or 5W-30 M1, either one is fine for year round use/strip racing/street.

For the SVT Lightning, the blown engine might benefit from a slightly thicker oil like 0W-40 or 10W-30 Mobil 1 - not too sure on this one. I think its a 5.4L SOHC V8 w/ a blower - the 5.4L SOHC V8s w/o the blower have about 255 hp and 350 lb-ft torque. Ford wants us to use 5W-20... but with a blower on there I'd probably stick with 0W-30, 5W-30, 10W-30, or 0W-40 just for that extra protection.

Not sure about the GM.
Warranty is not a concern for me, I know I will not loose an engine due to using Mobil 1 oil. I probably don't have a warranty on the Lighting now anyway, because I have ran it with a Superchips module installed. The Mustang GT is totally stock and not driven very hard. Maybe I should switch it to Mobil 1 10W-30.

The Lightning, when driven, is driven hard. Yes it is an Eaton M-112 roots type supercharger with 8-10 PSI of boost. I get it into boost almost everytime I drive it (after warmup of course), it's just too much power to resist. The 2000 model was underrated from the factory at 360HP, 440lb/ft torque. I have a conservatively tuned Superchip program on it that I believe adds around 25-30HP. I was just thinking the 15W-50 Mobil 1 would help protect this engine which produces a tremendous amount of heat under boost.

[ January 20, 2003, 10:10 PM: Message edited by: mracer ]
Hey mracer,
If you're looking for protection, then I think the 0W-40 & 15W-50 are your winners. Besides offering the heaviest barrier, the 15W-50 states that it contains more of the SuperSyn anti-wear additive than the other flavors, so it should protect the best. However, because it's the thickest it'll probably also retain a bit more heat than your other choices.

The 0W-40's also a great choice for protection, & it'll run cooler than the 15W-50. I'm using the 0W-40 in my turbocharged engine & like it a lot. (My gas mileage has actually improved a little from the 10W-30 Syntec I was using before.) I'd suggest the 0W-40 in all your vehicles, but really, either one of these two would be fantastic.
For the cars that are driven hard I would not recommend the Mobil 1 oil filter. Recent discussion on here is that this filter might be too restrictive to oil flow and causes more wear. Having a higher flow filter such as the K&N, Bosch Premium, or Walmart Supertech would protect better.
And, Mobil 1 0W-40 and 15W-50 are different oils from the xW-30 line, not just different viscosities. M1 0W-40 & 15W-50 meet the tougher ACEA A3-02 rating while the others are rated as A5 (which is superior to most oil's A1 rating). The 0W-40 is the only one to be rated as MB 229.5, Daimler-Chrysler's spec for longer drain interval and fuel saving.


Mobil 1, 0w-40 meets the ACEA A3/B4 ratings simply because it's thick enough to pass the min spec for high temp/high shear viscosity of 3.5 Cp @ 150C. But does this mean it's necessarily superior...?

SAE paper #981444 by Mobil shows that their 0w-30 and 0w-40 perform the same in both the ACEA A3/B3, gas/diesel engine tests, both in terms of wear and deposits. A baseline analysis of the Mobil 1, 5w-30 and 0w-40 shows they use basically the same additive levels, so there is little or no difference in chemistry.

If you had a situation where you weren't getting sufficient oil pressure with the 0w-30 or 5w-30, I'd say the 0w-40 would give you better protection. It's also conceivable that the 0w-40 would give you better valvetrain protection if you were functioning under boundary lubrication a good deal of the time ...However, I'm not sure this is the case for the majority of drivers ....

The DB 229.5 spec probably is based on ACEA A3/B4, but includes specific Mercedes engine tests. So the 0w-30/5w-30/10w-30 aren't going to pass this by default due to viscometrics - even if they could meet the requirements for wear/deposits ....Does that make sense?
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